1. Field of the Invention
The present invention relates to a helical substituted polyacetylene structure, a method for producing the same, a device structure using the polyacetylene structure, an ion transport film using the polyacetylene structure and a gas separation film using the polyacetylene structure.
2. Description of the Related Art
Under the circumstances that integration of electronic circuits is being progressed, organic devices using conductive organic materials such as organic semiconductors have currently attracted a great deal of attention. Organic devices have such advantages that organic devices are flexible, and if processes from solutions are feasible, inexpensive manufacturing of devices is enabled and processes applicable to large areas are enabled. Organic semiconductors include low molecular weight organic semiconductors such as pentacene and polymer semiconductors such as polythiophene. Polymer semiconductors are particularly compatible with solution processes, and hence attract attention as conductive materials suitable for large area processes and inexpensive processes. In particular, applications of substituted polyacetylenes to electronics materials have attracted attention; Japanese Patent Application Laid-Open Nos. 2004-256690 and 2003-142098 disclose that substituted polyacetylenes can be applied to conductive materials, EL elements, secondary batteries and the like.
Additionally, systems in which polyethers such as polyethylene oxide (PEO) and polypropylene oxide (PPO) are mixed with lithium salts or borates have hitherto been reported as ion conductive solid electrolytes to be used in electrochemical devices such as secondary batteries (U.S. Pat. No. 5,538,811); and polymers having sulfonic acid groups or carboxylic acid groups have been reported as proton conductive films (Japanese Patent Application Laid-Open No. 2002-334702).
The mechanism involved in the above-mentioned ion transport is a transport mechanism in which ions dissociated by being coordinated to polar group portions migrate by undergoing ligand exchange accompanied by the segment motion of the molecular chain. In this case, there is a problem that the conductivity of the electrolyte ion to be carrier is significantly affected by the segment motion of the polymer chain due to heat so as to be largely dependent on temperature, and hence the ion conductivity at low temperatures is degraded. Additionally, the transport mechanism concerned is a mechanism in which the transport is based on hopping over random polar group portions and hence cannot be said to be efficient.
Additionally, the production of oxygen enrichment films has hitherto been attempted for the purpose of obtaining high concentration oxygen from air. In this case, air is approximately assumed as a mixed gas composed of oxygen and nitrogen, the permeability coefficient ratio between nitrogen and oxygen (RO2/RN2) is used as the separation coefficient, and there has been demanded a material in which a high separation coefficient and a high oxygen permeability coefficient are compatible with each other.
Recently, there have been studied gas separation films which selectively separate gases by using films of polymers such as polysiloxane, and oxygen enrichment films are hoped for in the applications such as medical applications. Among such films, films of disubstituted polyacetylenes such as poly(trimethylsilylpropyne) and poly(trimethylsilyldiphenylacetylene) attract attention because these films each have a high oxygen permeability coefficient and a high separation coefficient (Japanese Patent Application Laid-Open No. S62-227411). However, even the performances of such films are not sufficient for practical applications, and there is a problem that due to the variation with time of the oxygen permeation, no stable separation performance can be maintained. Accordingly, the advent of polymer films being more stable in variation with time and having higher separation/permeation performances has been anticipated.
Additionally, there has been reported a technique in which a polymer is grown on a basal plate in a direction perpendicular to the basal plate by bonding a catalyst to the basal plate and by providing the thus processed basal plate with a monomer (Advanced Materials, Vol. 14, p. 1, p. 1130). It may be assumed that there can be obtained by using this technique a film in which the molecules are oriented in the film direction; however, the molecule involved is a polyolefin polymer molecule having a flexible main chain, and hence the orientation and the crystallinity of the film cannot necessarily be said to be high.